I created two 3D objects inside Illustrator, can Illustrator CC 2017 do some Pathfinder-like operations to these two objects? I want to intersect them, is it possible?
If you want to do the operations in 3D space then no, It’s not possible. Illustrators 3D features are very limited and you can’t directly access or affect the 3D model at all; it’s basically just an appearance effect that you apply to a 2D object.
You can expand the 3D objects and use Pathfinder etc., but all you’re doing then is working on static 2D projections of your 3D objects; which is probably not of much use.
If you need to build complex 3D models and/or directly manipulate the model then you’re better off using actual 3D modelling in software.